Area Forecast Discussion
Issued by NWS Charleston, SC
FXUS62 KCHS 251438
Area Forecast Discussion
National Weather Service Charleston SC
1038 AM EDT Tue Oct 25 2016
High pressure will prevail through Thursday. A weakening cold
front should approach Friday followed by more high pressure for
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Today: Dry/cooler high pressure will build over the area from the
north behind a cold front departing offshore. Aloft, the axis of a
longwave trough will continue shifting off the Eastern Seaboard,
further supporting weak cold air advection over the Southeast.
However, a full sun will help offset some cold air advection,
leading to afternoon temps in the low/mid 70s in the Tri-County
area and mid/upper 70s for areas south. A few locations could
reach 80 degrees south of I-16 and west of I-95 in Southeast
Georgia. Breezy and slightly cooler conditions will be possible
along the beaches. We could see winds gust between 15-25 mph into
early afternoon hours, especially along northeast facing beaches
such as Tybee Island, Hunting Island and Folly Beach.
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
Tonight: Surface high pressure will remain in place with mainly
clear skies expected. Some marine-based stratocumulus could move
onshore along parts of coastal McIntosh and Liberty Counties, but
models show the bulk of any such activity remain to the south
across Northeast Florida and far southern Southeast Georgia. There
will be a large range in temperatures overnight with lows ranging
from the mid 40s across interior Southeast South Carolina to the
lower 60s across coastal Georgia where the onshore flow from off
the Atlantic will help moderate temperatures. Breezy conditions
will linger at the beaches, especially from Hilton Head southward
along the Georgia coast.
Tuesday through Friday: The upper air pattern will consist of a
long wave trough axis remaining situated off the east coast during
the short term. Weak ridging will build over the region Wednesday
followed by a shortwave/trough Thursday into Friday. Broad surface
high pressure should be east of the Appalachians Wednesday,
shifting offshore Thursday as a system moves across the
Northeastern states. A weakening cold front should approach the
area from the northwest, dissipating as it passes through by
Friday morning. Another area of high pressure moving across the OH
Valley is expected to build into our region Friday. The pattern
will favor dry conditions. Models hint at perhaps some light
showers forming around the Gulf Stream Wednesday and Thursday,
then trying to approach the GA coast. But the probabilities are
very low and fairly dry air in place should prevent any showers
from making it inland. Even the cold front is expected to be dry
by the time is passes. As for temperatures, expect a warming trend
each day with Friday being the warmest due northwest downslope
winds, mostly sunny skies, and good thickness values for this time
of year. High temperatures will be well above normal by Friday.
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Surface high pressure is forecasted to build across the Southeast
Friday night and prevail into Saturday. A cold front should approach
our area from the north early next week, possibly passing through
our area. However, the front is expected to be dry. High pressure
will prevail behind the front. Temperatures will remain above normal
in the long term.
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
VFR conditions will prevail at the CHS and SAV terminals.
Extended Aviation Outlook: VFR.
Today: Northeast winds will continue to surge behind a cold front
pushing south/southeast of the coastal waters late this morning. A
Small Craft Advisory will continue for South Carolina waters off the
Charleston County coast where the pressure gradient is enhanced and
cold air advection is strongest. However, conditions should improve
by early afternoon. Elsewhere, northeast winds could gust as high as
15-20 kt at times. Seas will peak between 3-5 ft, highest in offshore
Tonight: Elevated northeast winds of 15-20 kt will persist across
the entire marine area within a pinched gradient regime induced by
high pressure to the north. The pressure gradient looks to relax
just enough to preclude frequent gusts to 25 kt, so Small Craft
Advisories are not currently anticipated. Seas will 3-4 ft
nearshore waters with 4-5 ft offshore waters.
Wednesday through Saturday: Broad surface high pressure should be
east of the Appalachians Wednesday, shifting offshore Thursday. A
weakening cold front should approach the area from the northwest,
dissipating as it passes through by Friday morning. Another area of
high pressure moving across the OH Valley is expected to build into
our region Friday and persist into Saturday. Winds and seas are
forecast to remain below any Small Craft Advisory levels into the
MARINE...Small Craft Advisory until 2 PM EDT this afternoon for AMZ350.